Abstract
Antiangiogenic therapy is an effective strategy to inhibit tumor growth. Endostar, as an approved antiangiogenesis agent, inhibits the newborn vascular endothelial cells, causing the decrease of integrin αvβ3 expression. Radiolabeled 3PRGD2, a novel PEGlayted RGD dimer probe (PEG4-E[PEG4-c(RGDfK)]2) showed highly specific targeting capability to integrin αvβ3, which could be used for monitoring the efficacy of Endostar antiangiogenic therapy. In this study, (68)Ga-3PRGD2 PET imaging was performed in Endostar treated/untreated Lewis Lung Carcinoma (LLC) mice on days 3, 7, 14, and 21 post-treatment for monitoring the tumor response to Endostar treatment, with the (18)F-FDG imaging as control. As a result, (68)Ga-3PRGD2 PET reflected the tumor response to Endostar antiangiogenic therapy much earlier (day 3 post-treatment vs day 14 post-treatment) and more accurately than that of (18)F-FDG metabolic imaging, which provides new opportunities to develop individualized therapeutic approaches, establish optimized dosages and dose intervals for effective treatment that improve the survival rate of patients.